THURSDAY, Sept. 20 (HealthDay News) -- Poorer people are more likely than the rich to receive a thyroid cancer diagnosis after the disease has progressed to a more advanced stage, according to a new study.

The study was scheduled for presentation Thursday at a meeting of the American Thyroid Association in Quebec City, Canada.

"Socioeconomic status is an important health indicator for a number of cancers and other diseases," the meeting's program co-chairwoman, Dr. Elizabeth Pearce, of the Boston Medical Center, said in an association news release. "These new data shed light on yet another area -- the time of thyroid cancer diagnoses -- in which there is a need to close the gap on this disparity."

Using a large thyroid cancer registry in Canada, researchers led by Dr. Stan Van Umm, of the Schulich School of Medicine and Dentistry at the University of Western Ontario, analyzed information on the cancer status, sex, age and socioeconomic status of nearly 1,600 patients diagnosed with thyroid cancer between January 1998 and December 2010.

Compared to younger, richer patients, older people and those with a lower average household income were more likely to receive a thyroid cancer diagnosis after it had progressed. There is, however, a 4 percent annual decline in the odds of being diagnosed with advanced thyroid cancer in old age, which suggests the disease is being detected sooner over time, the researchers said.

The earlier cancer is diagnosed, the easier it is to treat. The U.S. National Cancer Institute estimates that more than 56,000 Americans will be diagnosed with thyroid cancer this year, and about 1,800 will die of it.

Data and conclusions presented at meetings should be considered preliminary until published in a peer-reviewed medical journal.